We are searching data for your request:
Upon completion, a link will appear to access the found materials.
In 2013, Matthew borths, a postdoctoral student at the National Science Foundation (USA), found in a drawer the fossil remains of a specimen unknown to date: the Simbakubwa kutokaafrika.
His study of the remains, carried out together with paleontologist Nancy Stevens, from the University of Ohio (USA), has been published this week in the journal Journal of Vertebrate Paleontology.
Scientists have named the species as Simbakubwa kutokaafrika. “Simbakubwa means in Swahili 'great lion' because it is likely that the animal was at the top of the food chain in Africa, like modern lions, ”the experts explain.
On the other hand, "kutokaafrika, means from Africa"It is the oldest hyenodontid ever found.
An animal hidden in an African drawer
"When I opened the museum drawer, I found a row of long, sharp teeth, clearly belonging to a new species: Simbakubwa kutokaafrika," says Borths, lead author of the study with Stevens, who experienced the same feeling when he also found the fossils about years before in a drawer in the National Museum of Kenya.
Borths discovered that the remains of the drawer had been found at a site in Kenya between 1970 and 1980 and that researcher Stevens had been part of a team that had been studying it since 2010.
"I contacted her and she told me she had the same experience: opening the drawer and being amazed by the specimen," says Borths.
“The fossils were intriguing, both because of their size and because of their clear differences from other animals. Our team decided to study it and during this process, Matthew contacted me to ask if I could help, ”Stevens says.
Since Borths was currently making his thesis on hyenodontids He turned out to be the perfect person to lead the analysis of this creature. The two then decided to collaborate to re-analyze the museum's fossil collection in 2017.
Details of Simbakubwa kutokaafrika
The Simbakubwa features They were obtained from the analysis of part of the skull, teeth and other remains found.
According to the results, this animal it was bigger than a polar bear, with a skull as large as that of a rhinoceros, and huge, piercing fangs. The authors suggest that this massive carnivore would have been a intimidating predator in East Africa of primitive apes and monkeys.
"The specimen's teeth had characteristics that we had never seen in closely related carnivores," says Borths. “There are additional folds of enamel on part of the molar and the canine has a serrated edge, like a steak knife. Most of the canines in this group are broad and fang-shaped rather than serrated and narrow, ”kite.
The team compared the fossils with those of other closely related hyenodontids, such as Hyainailouros found in Europe, Pakistan and India and Megistotherium discovered in North Africa.
"Simbakubwa shares many characteristics with these other species, such as the presence of three specialized teeth that chop the meat and that are mostly blade-shaped ridges that would have given these large carnivores the ability to cut in the shape of a scissor", Borths explains.
However, “they also have differences in the way teeth are joined -such as stretch marks on canines, extra enamel on molars and narrower dentition in general- and on the ankle, which helped us to recognize this animal as a different species ”, he adds.
They also conducted a phylogenetic analysis to place Simbakubwa within the family tree of hyenodontids. Based on their findings, Simbakubwa turned out to be the oldest of the gigantic hyenodontids found to date ago 22 million years.
Simbakubwa and his ancestors
Although Simbakubwa means 'great lion', this animal was not closely related to big cats, nor with any other carnivore mammal alive today.
Instead, the creature belonged to an extinct group of mammals called hyenodontids, which were the first carnivorous mammals in Africa. For about 45 million years after the extinction of the dinosaurs, they were the biggest predators in Africa.
Then, after millions of years of near isolation on the African continent, the tectonic movements of the Earth's plates connected Africa with the northern continents, allowing floral and faunal exchange. Around the time of Simbakubwa, relatives of cats, hyenas, and dogs began arriving in Africa from Eurasia.
To be Simbakubwa of the oldest of the hyenodontids, this lineage of giant carnivores probably originated from the African continent and it moved north to flourish for millions of years.
Finally, hyenodontids around the world became extinct and the reason is unknownBut ecosystems were changing rapidly as the global climate became drier. "Simbakubwa's gigantic relatives were among the last hyenodontids on the planet”Says Borths.
"It is a fundamental fossil that demonstrates the importance of museum collections in understanding the history of evolution”Stevens says. Simbakubwa is a window into a bygone era. As ecosystems changed, a key predator disappeared, heralding Cenozoic faunal transitions that eventually led to the evolution of modern African fauna, "he concludes.
Borths, M. and Stevens, N. «Simbakubwa kutokaafrika, Gen. et sp. nov, (hyanailourinae, hyaenodonta, creodonta, mammalia), a gigantic carnivore from the earliest miocene of Kenya », Journal of Vertebrate Paleontology, April 2019, DOI: http://www.tandfonline.com/10.1080/02724634.2019.1570222.